PHP DateInterval __construct() Method

The PHP DateInterval::__construct() method creates a new DateInterval object.

Syntax

public DateInterval::__construct(duration)

Parameters

duration

Required. Specify an interval. The format starts with the letter P, for period. Each duration period is represented by an integer value followed by a period designator. If the duration contains time elements, that portion of the specification is preceded by the letter T. The duration Period designators are:

Y years
M months
D days
W weeks. Converted into days. Prior to PHP 8.0.0, can not be combined with D.
H hours
M minutes
S seconds

Examples: Two days is represented as P2D. Two seconds is represented as PT2S. Six years and five minutes is represented as P6YT5M.

Note: The unit types must be entered from the largest scale unit on the left to the smallest scale unit on the right. Hence, years before months, months before days, days before minutes, etc. Therefore, one year and four days must be represented as P1Y4D, not P4D1Y.

Return Value

Returns a new DateInterval object on success.

Exceptions

Throws Exception if the duration cannot be parsed as an interval.

Example: creating DateInterval object

The example below shows the usage of DateInterval::__construct() method.

<?php
//creating a DateInterval object
$interval = new DateInterval('P1W2D');

//displaying the result
print_r($interval);
?>

The output of the above code will be:

DateInterval Object
(
    [y] => 0
    [m] => 0
    [d] => 9
    [h] => 0
    [i] => 0
    [s] => 0
    [f] => 0
    [weekday] => 0
    [weekday_behavior] => 0
    [first_last_day_of] => 0
    [invert] => 0
    [days] => 
    [special_type] => 0
    [special_amount] => 0
    [have_weekday_relative] => 0
    [have_special_relative] => 0
)

Example: using DateInterval object

The DateInterval object can be used to modify a given DateTime object. Consider the example below:

<?php
//creating a DateTime object
$date = new DateTime("10-May-2015");

//displaying the date
echo "Original Date: ".$date->format('d-M-Y')."\n";

//creating a DateInterval object
//1 year 2 months 15 days
$interval = new DateInterval('P1Y2M15D');

//adding the date interval to the date
$date->add($interval);

//displaying the result
echo "Modified Date: ".$date->format('d-M-Y')."\n";
?>

The output of the above code will be:

Original Date: 10-May-2015
Modified Date: 25-Jul-2016

❮ PHP Date and Time Reference